1. Field of the Invention
This invention relates to treating aneurysms by applying hardening/softening agents (such as RF energy) to hardenable/softenable substances (such as collagen), along with associated steps.
2. Description of Related Art
An aneurysm is a localized abnormal dilation of a blood vessel, typically an arterial blood vessel, and typically due to a weakening of the wall of the blood vessel. If left untreated, the aneurysm generally becomes worse under the fluid pressure of blood flowing through the blood vessel, and eventually bursts or ruptures, with catastrophic results for the fluid-delivery capacity of the blood vessel. When the blood vessel is critical to functional operation of a major bodily system, such as when the blood vessel is important for the heart or brain, a catastrophic result for the blood vessel is also catastrophic for the patient. For example, one typical location for aneurysm is the aorta, the largest blood vessel carrying blood leaving the heart; a ruptured aortic aneurysm is almost always fatal.
One known method of treating aortic aneurysms is to surgically insert a stent graft into the aorta, thus strengthening the aortic aneurysm against bursting or rupture. While this known method achieves the general goal of reducing likelihood of fatality from the aortic aneurysm, it has the drawback that it generally requires surgery of the aorta. This surgery involves a substantial risk to the patient. This known method also has the drawback that the aneurysm remains a weak area in the blood vessel wall, with the potential for further weakening, and thus may require further corrective action later. Moreover, this known method has the drawback that it is unsuited for treatment of blood vessels which are too small for a stent graft or too inaccessible for such surgery, such as many blood vessels in the brain.
A second known method of treating aneurysms is available for smaller blood vessels, such as those in the brain. In this known method, small metallic coils (sometimes called Guigeliami coils) are disposed in a bubble or pocket formed by the aneurysm outside the main fluid flow of the blood vessel. The metallic coils are generally delivered to the site of the bubble or pocket using a catheter. Once present at the site, the metallic coils fill the region defined by the aneurysm, and may prevent enlargement of the aneurysm by dissipating the force of blood flow into the region of the aneurysm. This known method similarly has the drawback that the aneurysm remains a weak area in the blood vessel wall, with the potential for further weakening, and thus may require further corrective action later. Moreover, this known method has the drawback that it is unsuited for treatment of blood vessels in which the vessel wall is weakened, but has not yet expanded to form a bubble or pocket into which the small metallic coils may be inserted and be expected to remain.
Accordingly, it would be advantageous to provide a superior technique for treating aneurysms and other weakened body structures.